Lecture 20 Flashcards
(26 cards)
What is relative dating?
Relative dating is a method used to determine the age of rocks and fossils in relation to one another.
True or False: Relative dating provides an exact age of a rock or fossil.
False
What principle states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom?
The Law of Superposition.
Fill in the blank: The principle of __________ allows scientists to determine the relative ages of rock layers based on their position.
superposition
What is the significance of index fossils in relative dating?
Index fossils are used to identify and date the time period in which they existed, helping to correlate rock layers.
Which of the following is NOT a method of relative dating? (A) Stratigraphy (B) Radiometric dating (C) Biostratigraphy
B) Radiometric dating
What is the principle of original horizontality?
The principle states that layers of sediments are originally deposited horizontally under the action of gravity.
True or False: The principle of cross-cutting relationships states that a rock or fault that cuts through another rock is younger than the rock it cuts.
True
What is an unconformity in geology?
An unconformity is a surface that represents a break in the geological record, indicating that deposition stopped for a period of time.
Short Answer: Name one type of unconformity.
Angular unconformity.
What does the term ‘stratigraphy’ refer to?
Stratigraphy refers to the study of rock layers and layering.
Fill in the blank: Fossils that are used to define and identify a particular time period are known as __________.
index fossils
True or False: Relative dating can only be used on sedimentary rocks.
False
What role do fossils play in relative dating?
Fossils help to correlate the ages of rock layers and understand the sequence of events in geological history.
Which principle is applied when determining the relative age of a rock layer by examining the fossils it contains?
Biostratigraphy.
Multiple Choice: Which of the following is an example of a relative dating technique? (A) Potassium-argon dating (B) Carbon dating (C) Law of Superposition
C) Law of Superposition
What is the main limitation of relative dating?
It cannot provide an exact age or a numerical date for the rocks or fossils.
True or False: Relative dating can be used in both geology and archaeology.
True
What does the term ‘chronostratigraphy’ refer to?
Chronostratigraphy is the branch of stratigraphy that deals with the age of rock layers.
Fill in the blank: The __________ is a tool used to correlate the ages of rock layers across different geographical areas.
geologic time scale
What is a key characteristic of an index fossil?
It must be widespread and only exist for a short geological time.
True or False: The principle of faunal succession states that different fossil species appear and disappear in a definite and recognizable order.
True
Short Answer: What can cause a gap in the geological record?
Erosion or non-deposition.
What is the purpose of using relative dating in geological studies?
To establish the sequence of geological events and the relative ages of rock formations.
